CA-GILEAD-SCIENCES,-INC.

Gilead Sciences, Inc. (NASDAQ: GILD) today announced detailed 48-week
results from two Phase 3 studies (Studies 1489 and 1490) evaluating the
efficacy and safety of a fixed-dose combination of bictegravir (50 mg)
(BIC), a novel investigational integrase strand transfer inhibitor
(INSTI), and emtricitabine/tenofovir alafenamide (200/25mg) (FTC/TAF), a
dual-NRTI backbone, for the treatment of HIV-1 infection in
treatment-naïve adults. In the ongoing studies, BIC/FTC/TAF was found to
be statistically non-inferior to regimens containing dolutegravir (50mg)
(DTG) in combination with a dual-NRTI backbone. The data were presented
in two late-breaker sessions [MOAB01 and TUPDB02] at the 9th IAS
Conference on HIV Science (IAS 2017) in Paris.

“Physicians continue to look for treatment regimens with simple,
convenient dosing that can sustain virologic suppression with a safety
profile that is appropriate for most HIV patients,” said Joel Gallant,
MD, MPH, Medical Director of Specialty Services at Southwest CARE Center
in Santa Fe, N.M. and lead author of Study 1489. “Combinations of an
integrase inhibitor plus a dual-NRTI backbone have become a standard of
care for initial treatment of HIV. In clinical trials, the
investigational regimen of BIC/FTC/TAF has been well tolerated with low
rates of discontinuations due to adverse events, a high barrier to
resistance and few drug interactions.”

“These data reinforce the safety and efficacy profile consistently seen
in other trials evaluating regimens based on the FTC/TAF combination,”
said Paul Sax, MD, Clinical Director of the Division of Infectious
Diseases at Brigham and Women’s Hospital, Boston, Professor of Medicine
at Harvard Medical School and lead author of Study 1490. “These results
suggest that the combination of bictegravir with FTC/TAF has the
potential to be appropriate for a broad range of HIV patients, including
those with mild to moderate renal impairment.”

A separate analysis investigated the effect of the two regimens on
changes in bone mineral density (BMD) and measures of renal function.
Mean percentage changes in BMD from baseline to Week 48 were -0.83
percent for BIC/FTC/TAF vs. -0.60 percent for ABC/DTG/3TC (p=0.39) in
lumbar spine, and -0.78 percent for BIC/FTC/TAF vs. -1.02 percent for
ABC/DTG/3TC (p=0.23) in total hip. No differences were noted between the
treatments in changes from baseline to Week 48 for estimated glomerular
filtration rate (eGFR) or proteinuria. Lipid changes were not
significantly different between the two arms. No patients randomized to
either arm developed treatment-emergent resistance and discontinuations
due to adverse events were low in both groups (0.0 percent (n=0) for
BIC/FTC/TAF vs. 1.3 percent (n=4) for ABC/DTG/3TC). The most commonly
reported adverse events (all grades) were nausea (10 percent for
BIC/FTC/TAF vs. 23 percent for ABC/DTG/3TC), diarrhea (13 percent vs. 13
percent) and headache (11 percent vs. 14 percent).

In Study 1490, a total of 645 treatment-naïve adults with HIV were
randomized 1:1 to receive BIC/FTC/TAF or DTG+FTC/TAF. At Week 48, 89.4
percent (n=286/320) of patients taking BIC/FTC/TAF and 92.9 percent
(n=302/325) of patients taking DTG+FTC/TAF achieved the primary endpoint
of HIV-1 RNA levels less than 50 copies/mL (difference: -3.5 percent, 95
percent CI: -7.9 percent to 1.0 percent, p=0.12). No patients in either
treatment arm developed resistance to any of the study drugs. Lipid
changes were not significantly different between the two arms, and there
were no renal discontinuations or cases of proximal renal tubulopathy.
Discontinuations due to adverse events were low in both treatment arms
(1.6 percent (n=5) for BIC/FTC/TAF vs. <1.0 12 percent (n="1)" for dtg+ftc taf). the most commonly reported adverse events (all grades) were headache (13 bic ftc taf vs. taf) and diarrhea (12 percent). < p>

“The Phase 3 findings presented at IAS 2017 demonstrate that a
single-tablet combination of bictegravir with the FTC/TAF backbone may
deliver an important novel triple-therapy HIV treatment,” said Norbert
W. Bischofberger, PhD, Gilead’s Executive Vice President, Research and
Development and Chief Scientific Officer. “These data in treatment-naïve
patients, and data from two additional Phase 3 studies in
treatment-experienced patients, formed the basis of our regulatory
applications in the United States and the European Union.”

In addition to Studies 1489 and 1490, 48-week data from two other
ongoing studies evaluating BIC/FTC/TAF among virologically suppressed
adult patients (Studies 1844 and 1878) are also part of the regulatory
submissions in the U.S. and EU.

Bictegravir in combination with FTC/TAF as a single tablet regimen is an
investigational treatment that has not been determined to be safe or
efficacious and is not approved anywhere globally.

Gilead Sciences is a biopharmaceutical company that discovers, develops
and commercializes innovative therapeutics in areas of unmet medical
need. The company’s mission is to advance the care of patients suffering
from life-threatening diseases. Gilead has operations in more than 30
countries worldwide, with headquarters in Foster City, California.

For nearly 30 years, Gilead has been a leading innovator in the field of
HIV, driving advances in treatment, prevention, testing and linkage to
care, and cure research. Today, it’s estimated that more than 10 million
people living with HIV globally receive antiretroviral therapy provided
by Gilead or one of the company’s manufacturing partners.

Forward-Looking Statement

This press release includes forward-looking statements within the
meaning of the Private Securities Litigation Reform Act of 1995 that are
subject to risks, uncertainties and other factors, including the
possibility that regulatory authorities may not approve BIC/FTC/TAF in
the currently anticipated timelines, and marketing approvals, if
granted, may have significant limitations on their use. As a result,
BIC/FTC/TAF may never be successfully commercialized. These risks,
uncertainties and other factors could cause actual results to differ
materially from those referred to in the forward-looking statements. The
reader is cautioned not to rely on these forward-looking statements.
These and other risks are described in detail in Gilead’s Quarterly
Report on Form 10-Q for the quarter ended March 31, 2017, as filed with
the U.S. Securities and Exchange Commission. All forward-looking
statements are based on information currently available to Gilead, and
Gilead assumes no obligation to update any such forward-looking
statements.

For more information on Gilead Sciences, please visit the company’s
website at www.gilead.com,
follow Gilead on Twitter (@GileadSciences) or call Gilead Public Affairs
at 1-800-GILEAD-5 or 1-650-574-3000.